Conventionally, an information retrieving technique intended for characters has been widely used. However, with respect to a retrieving technique intended for video image, there are few realized examples and various attempts are still being made at present. Among them, moving picture retrieving methods such as a method using an image recognizing technique, a method using a scene extracting technique, and the like have been being studied from various viewpoints.
For example, in a VOD (Video On Demand) system in which a moving picture server and a database server are combined, the contents (of a moving picture) can be retrieved by a keyword retrieval of a title name or the like. The title name, however, does not always properly express the contents. Under the present circumstances, in many cases, the contents can be recognized as a result from playing them back.
In order to solve the problem, as disclosed in Japanese Unexamined Patent Application No. 2-260075, the applicant of the invention has proposed a video browser technique with a view to showing a moving picture so as to be recognized at sight. According to the video browser technique, index pictures as so-called digest still pictures are generated on the basis of partial images sampled from a series of still pictures which form a moving picture through a moving slit window and are listed in accordance with the time, thereby enabling the rough contents of the moving picture to be recognized at a glance.
By the video browser technique, since the contents of a moving picture of an enormous amount recorded in an invisible state are displayed in the form of still pictures compressed according to the time, the contents of the moving picture can be immediately grasped.
In the above-mentioned publication regarding the video browser technique, however, only the method of using a slit window moving in the vertical direction or a slit window moving in the horizontal direction is disclosed as a method of sampling partial images through a moving slit window from a series of still pictures constructing a moving picture. An index picture cannot be generated in proper, various modes according to the kind and use of the material (moving picture), the condition of a system configuration, and the like.